1. Field of the Invention
The present invention generally pertains to positioning and maintaining an expandable acetabular cup in a bone cavity. The present invention finds a particularly advantageous application in inserting an acetabular cup in the field of cementless hip prosthetics.
2. Description of the Prior Art
Presently known as acetabular implants comprising a hemispherical acetabular cup of the type that are “press fit”. This type of acetabular cup is implanted in a bone cavity previously enlarged by simple impaction or compression. By positioning the acetabular cup in the bone cavity under pressure it is unfortunately not possible to proceed with a gradual entry of the acetabular cup in the cavity which would permit to correct positioning errors. Therefore, a plurality of press fit acetabular cups are inadequately implanted such that it is not possible to rectify the situation while preserving the integrity of the bone tissue bordering the prosthetic implant.
The difficulties of positioning the acetabular cup in the acetabulum of the patient are principally caused by the installation of the acetabular cup in the bone with a high level of constraints for obtaining optimal implant stability.
Moreover, the configuration of the hemispherical part of the acetabular cup can damage the bone surface during a forced implantation by way of a guide/impacteur. What's more, screws often need to be installed in the bone to assure the primary stability of the implant.